自修复聚合物材料用微胶囊的研究进展

介绍了微胶囊自修复聚合物材料的自修复机理,阐述了微胶囊的制备技术。讨论了近年来在该领域最新的研究成果,展望了微胶囊自修复复合材料的研究方向。     

外援型聚合物基自修复复合材料研究进展

聚合物基自修复复合材料是一种重要的的智能复合材料。本文就近年来聚合物基自修复复合材料的研究进展进行了系统综述,并以外援型热固性聚合物基自修复复合材料为重点,详细介绍了几种典型的外援型修复方法,主要包括微胶囊型自修复、中空纤维型自修复、微脉管型自修复、热塑性自修复,系统地阐述了这几种自修复方法的修复机理及特点并分析比较其优劣,展望了聚合物基自修复复合材料的应用前景及发展方向。     

微胶囊型自修复聚合物材料的研究进展

聚合物材料在使用过程中,内部不可避免地会产生裂纹。由于这些裂纹难以被检测和及时修复往往会缩短材料使用寿命。主要介绍微胶囊型自修复聚合物复合物材料的自修复机理,以及微胶囊、催化剂、修复剂等因素对材料自修复效率的影响。着重介绍该领域最新研究进展,并对微胶囊自修复聚合物复合材料的研究前景进行了展望。     

微胶囊型自修复聚合物复合材料研究进展

介绍了聚合物复合材料自修复的概念和机理,自修复体系的组成和要求以及自修复材料的评价方法。综述了最近几年对影响复合材料自修复效果的4个方面因素(微胶囊的含量及粒径、修复剂的种类、催化剂的用量和粒子尺寸以及体系混合次序)的研究进展。     

微胶囊自修复技术及其在聚合物基复合材料中的应用

论述了微胶囊自修复技术以及自修复机理,重点阐述了微胶囊自修复技术在聚合物基复合材料中应用的最新研究成果.通过分析聚合物基自修复复合材料对微胶囊结构和性能的要求,指出了今后的发展方向和应用前景.     

异氰酸酯型微胶囊自修复涂料的研究进展

介绍了微胶囊自修复涂料种类、异氰酸酯型微胶囊自修复涂料的修复机理以及微胶囊自修涂料自修复效果的评价方法。综述了IPDI型、HDI型微胶囊自修复涂料的研究进展。     

自修复聚合物材料用微胶囊的研究进展

自修复材料是一种新型的智能材料。将微胶囊埋植于材料中是实现其自修复的一种方法,也是目前该领域的研究热点之一。本文介绍了微胶囊型自修复的概念和原理,综述了近几年来DCPD型微胶囊、环氧树脂型微胶囊、硅油型微胶囊以及其他微胶囊型自修复的发展状况,并着重介绍了最新研究成果,对微胶囊型自修复材料的研究前景进行了展望。     

氟硅烷改性微胶囊复合材料的制备与性能研究

以脲醛树脂（UF）作为壁材,环氧树脂E-51(EP)作为修复剂,采用原位聚合法制备了自修复微胶囊,并采用硅烷偶联剂1H,1H,2H,2H-全氟葵基三甲氧基硅烷（KBM-7803）对壁材表面进行处理,加入环氧树脂中,固化得到改性微胶囊复合材料。通过傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）、激光粒度仪（PSDA）、电子万能试验机等分析测试技术对改性前后的微胶囊及改性微胶囊复合材料的微观形貌和自修复性能进行表征与分析。结果表明,所制备的微胶囊与基体材料相容性较好,当KBM-7803改性微胶囊的添加量为6wt%时,复合材料的自修复效率达到最高值77.4%,具有良好的自修复性能。     

碳纳米管微胶囊制备与应用进展

介绍了碳纳米管(CNTs)微胶囊的组成及特性,探讨了CNTs微胶囊的制备方法、影响因素以及在复合材料自修复、相变材料改性、缓释和贮能材料改性等方面的应用,并总结了CNTs微胶囊研究存在的问题与不足,提出了未来可能的研究方向。     

球形/球柱形微胶囊自修复水泥基复合材料修复效率数值模拟

水泥基复合材料因其固有的脆性和较低的抗拉强度,在工程结构中不可避免会发生开裂。胶囊法自修复系统为水泥基材料基体开裂的修复和延缓潜在危害提供了一种可行的方法。借助扩展有限元方法,模拟了微胶囊自修复水泥基模型材料内微裂缝的产生、扩展、断裂过程及胶囊破裂行为,验证了裂缝迫使胶囊发生破裂的概率;应用复合材料理论,计算出了不同掺量下球形/球柱形微胶囊修复前后水泥基复合材料的有效弹性模量,表征了该复合材料的修复效率。     

Novel multifunctional microcapsule and its cyanate ester resin composites with self-healing ability and gamma radiation shielding ability

Resin-based composites used in spacecraft face risks from space debris and high-energy charged particles during their long-term service in the space environment. This work proposes a novel microcapsule (MC) and its cyanate ester (CE) resin-based composites (CE/MCs) with self-healing ability and gamma radiation shielding ability. The multifunctional epoxy/lead tungstate (EP@PWO) microcapsules are developed through self-assembly method and in-situ precipitation method. These microcapsules and curing agent 4,4′-diaminodiphenylsulfone (DDS) are incorporated into the CE resin to form resin-based composites with low curing temperature, self-healing ability, and gamma radiation shielding ability. Various approaches including chemical characterizations (X-ray diffractometer, fourier-transform infrared, energy dispersive spectrometer), microscopy (optical microscope, scanning electronic microscope), and thermal analysis (differential scanning calorimeter, thermogravimetric analysis) are utilized to demonstrate the successful encapsulation of the EP resin by PWO shell and good thermal stability of this material. The mechanical property, self-healing ability, and gamma radiation shielding property are investigated via fracture toughness test and using a NaI (Tl) spectrometer. In comparison with pure CE resin, the fracture toughness of the CE/MCs composites can increase by 66.5%, and the self-healing efficiency can reach up to 56%, indicating that the microcapsules have good toughening and self-healing abilities. The microcapsules and their composites also exhibit good gamma radiation shielding properties.     

微胶囊技术及其在复合材料中的应用

介绍了微胶囊技术的概念及其种类,归纳总结了微胶囊的表征方法。根据微胶囊近年来的研究,重点阐述了微胶囊技术在聚合物基复合材料损伤自修复过程中的应用研究。     

自修复微胶囊及其防护涂层应用研究进展

随着自修复技术的不断发展,微胶囊在防护涂层等领域日益表现出突出的应用优势。文中综述了单壁、双壁自修复微胶囊的配方设计与结构性能以及微胶囊的模拟仿真研究现状,综述了以异氰酸酯、环氧树脂、缓蚀-腐蚀抑制剂、植物油为修复剂的自修复微胶囊在防护涂层中的应用研究进展,总结了现有微胶囊自修复材料存在的问题,提出了将自修复微胶囊与分子动力学模拟相结合的研究方法,希望通过该方法建立微胶囊宏微观结构与性能的关联性规律,实现对微胶囊自修复机理的深入探索与研究。     

Enhanced thermo-mechanical properties of acrylic resin reinforced with silanized alumina whiskers

The acrylic resin reinforced with silanized alumina whiskers with self-healing (SH) agents was synthesized. The self-healing system consisted of microcapsules with the healing agent dicyclopentadiene (DCPD) and modified Grubbs' catalyst in PS electrospun nanofibers. The content of alumina whiskers was 3% w/w, and the concentration of PS fibers and UF microcapsules in the samples were 1% w/w each. The embedded silanized alumina whiskers achieved higher T_g and absorbed impact energy in relation to unmodified alumina whiskers. The nanoindentation test revealed the reduced modulus increased for about 65% and hardness increased is about 90% for composites with silanized whiskers. Cracks were induced on the composite surface using the low energy impact test machine. The self-healing efficiency of 74% was approved by the repeated impact test after 96 h.     

吸水性微胶囊界面修饰提高水泥基材料抗渗性研究

在自修复水泥基材料中,微胶囊与水泥基体间的界面结合决定着微胶囊被裂缝触发的概率,从而影响自修复效果。本文针对吸水性微胶囊的界面结合问题,利用硅烷偶联剂KH550修饰环氧/海藻酸钙微胶囊表面,以改善其与水泥基体间的界面结合情况。采用X射线光电子能谱仪、电感耦合等离子体发射光谱仪等表征硅烷偶联剂在微胶囊表面的键合状况,利用压汞法分析水泥基材料的孔结构,并测试水泥基材料的抗渗性与自修复效果。结果表明,硅烷偶联剂能够与微胶囊外壁的海藻酸钙发生化学键合,微胶囊与水泥基体间的界面结合得到有效改善,水泥基体中有害孔数量减少,无害孔和少害孔数量增加,水泥基材料的抗渗性和自修复效果获得提升。     

Preparation of Tung Oil-Loaded PU/PANI Microcapsules and Synergetic Anti-Corrosion Properties of Self-Healing Epoxy Coatings

Tung oil is used as a catalyst-free repair agent. Tung oil-loaded polyurethane (PU) microcapsules are prepared by interfacial polymerization in a SiO₂-stabilized Pickering emulsion system, polyaniline (PANI) is deposited in situ on the PU microcapsule surface, and tung oil-loaded PU/PANI double-layer shell microcapsules are obtained. Synthesized PU/PANI microcapsules showed the characteristic dark-green color of conductive PANI. The average particle size is 31.1 ± 8.1 µm and the core content is 45.1 ± 4.3 wt%. The microcapsules have a good thermal stability, and the chemical structure of the PU/PANI wall and tung oil core is confirmed by Fourier transform infrared analysis. Self-healing anti-corrosion coatings are prepared by adding 10 wt% microcapsules into epoxy resin. The corrosion resistance properties of the self-healing coating are evaluated by immersing scratched coatings in 10 wt% NaCl solution for 15 days. The self-healing coating with 10 wt% tung oil-loaded PU/PANI microcapsules have the best anti-corrosion property, and slight corrosion do not occur until 15 days after immersion in salt solution. The self-healing and anti-corrosion mechanism are revealed. The tung oil core and the PANI wall of microcapsules contributed synergistically to the excellent self-healing and anti-corrosion properties of the coating through the formation of self-healing films and passivation layers.     

Effect of microcapsule size on the performance of self-healing polymers

The influence of microcapsule diameter and crack size on the performance of self-healing materials is investigated. These epoxy-based materials contain embedded Grubbs' catalyst particles and microencapsulated dicyclopentadiene (DCPD). Autonomic repair is triggered by rupture of the microcapsules in response to damage, followed by release of DCPD into the crack plane where it mixes with the catalyst and polymerizes. The amount of liquid that microcapsules deliver to a crack face is shown to scale linearly with microcapsule diameter for a given weight fraction of capsules. In addition, self-healing performance reaches maximum levels only when sufficient healing agent is available to entirely fill the crack. Based on these relationships, the size and weight fraction of microcapsules can be rationally chosen to give optimal healing of a predetermined crack size. By using this strategy, self-healing is demonstrated with smaller microcapsules and with lower weight fractions of microcapsules than have been possible in previous self-healing systems.     

Self-healing linear polymers based on RAFT polymerization

Self-healing polystyrene (PS) composites were fabricated, in which glycidyl methacrylate (GMA)-loaded microcapsules were embedded. Because the matrix PS was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization, it kept living characteristics and was able to resume the polymerization so long as monomers were available. Upon damage of the composites, the GMA released from the broken capsules infiltrated into the cracks and was copolymerized with the matrix PS according to the above mechanism. As a result, the cracked planes were covalently re-bonded, offering recovery of impact strength. Compared to the self-healing system based on atom transfer radical polymerization (ATRP), which is also an approach of living polymerization, the current one possesses robust vitality in air and eliminates the possibility of acceleration of matrix degradation aroused by metal ions. Additionally, the resultant self-healing PS composites have an advantage in coloration, which is important for satisfying esthetic requirement in practice.     

Study of factors related to performance improvement of self-healing epoxy based on dual encapsulated healant

Our earlier work developed epoxy based self-healing composites with embedded dual microcapsules, which contain unreacted epoxy as the polymerizable component and mercaptan and tertiary amine catalyst as the hardener, respectively. Self-healing was allowed to proceed rapidly, offering attractive repair effectiveness. To give full play to the healing agent, influences of a series of factors on healing chemistry of the composites were studied in this paper. It was found that strong alkality of the catalyst, high activity of mercaptan, and low viscosity of the encapsulated epoxy prepolymer ensured high healing efficiency and rate of healing. In addition, matching of the microcapsules' sizes and fractions was critical for keeping stoichiometric ratio of the components at the damage areas, as required by the mechanism of the healing reaction (i.e. addition polymerization). Homogeneous dispersion of the capsules under proper stirring speed led to timely contacts between the healant fluids flowing out of the fractured capsules. Larger microcapsules favored filling of the cracks in terms of larger amount of the released healing agent, while smaller ones facilitated mixing and interdiffusion of the ingredients. The results provided key data for optimizing the self-healing system.     

环氧树脂微胶囊与潜伏性固化剂自修复体系断裂韧性的研究

微胶囊二元自修复系统对聚合物基复合材料在使用中产生的微小裂纹具有修复作用,但微胶囊和固化剂的加入会对基体材料的断裂韧性产生影响。本文研究了环氧树脂微胶囊和咪唑类潜伏性固化剂对聚合物基复合材料基体材料的断裂韧性的影响。采用环氧树脂E-51作为基体材料,三乙烯四胺为常温固化剂,咪唑类衍生物2MZ-Azine和实验室自制的包含环氧树脂芯材的微胶囊为材料制作断裂韧性拉伸试样。实验结果表明,当微胶囊的含量达到一定比例之前,基体材料的断裂韧性随着微胶囊含量的增加而增强,当微胶囊含量超过此比例后,基体材料的断裂韧性随着微胶囊含量的增加而减小,潜伏性固化剂的加入会增大基体材料的断裂韧性。这与环氧树脂材料增韧理论相符合。